In scanning laser devices, laser light is reflected off one or more scanning mirrors to generate a scanning pattern. For example, in scanning laser projectors, images are projected by scanning laser light into a pattern with a scanning mirror, with individual pixels generated by modulating the laser light. Similarly, laser depth scanners generate depth maps by scanning laser light into a pattern with a scanning mirror and measuring the laser light reflected back.
One issue with scanning laser devices is the need to manage mechanical distortion in the scanning mirrors. Specifically, as a scanning mirror rotates forces are applied to the mirror and these forces can cause distortions in the mirror surface. Furthermore, as mirror rotation angles and/or speed have increased in modern devices the forces applied to the mirror have also increased. These increased forces can result in increased distortions in the mirror surface. When such distortions are large enough the resulting scanning pattern can be distorted and image quality can be noticeably reduced. Thus, there is a need for devices and methods for managing the mirror distortion in scanning laser devices.
Another issue with scanning laser devices is device complexity. Specifically, there has been an increasing need for more compact scanning laser device size while performance requirements have been maintained or increased. To meet these needs, more scanners with more complex structure and shapes have been proposed. Unfortunately, such designs can also lead to increased manufacturing complexity, which can reduce yield and increase costs. Thus, there is a need for devices and methods that facilitate performance and compact size while reducing manufacturing complexity and cost.